20820631 has 12 divisors (see below), whose sum is σ = 23874912. Its totient is φ = 18086016.

The previous prime is 20820617. The next prime is 20820649. The reversal of 20820631 is 13602802.

It is not a de Polignac number, because 20820631 - 2⁹ = 20820119 is a prime.

It is a super-2 number, since 2×20820631² = 866997350476322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20820691) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 751 + ... + 6496.

It is an arithmetic number, because the mean of its divisors is an integer number (1989576).

Almost surely, 2^20820631 is an apocalyptic number.

20820631 is a deficient number, since it is larger than the sum of its proper divisors (3054281).

20820631 is a wasteful number, since it uses less digits than its factorization.

20820631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7290 (or 7277 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 20820631 is about 4562.9629628127. The cubic root of 20820631 is about 275.1046697977.

The spelling of 20820631 in words is "twenty million, eight hundred twenty thousand, six hundred thirty-one".